Drug delivery devices for setting and dispensing a single or multiple doses of a liquid medicament are as such well-known in the art. Generally, such devices have substantially a similar purpose as that of an ordinary syringe.
Drug delivery devices, in particular pen-type injectors have to meet a number of user-specific requirements. For instance, with patient's suffering chronic diseases, such like diabetes, the patient may be physically infirm and may also have impaired vision. Suitable drug delivery devices especially intended for home medication therefore need to be robust in construction and should be easy to use. Furthermore, manipulation and general handling of the device and its components should be intelligible and easy understandable. Moreover, a dose setting as well as a dose dispensing procedure must be easy to operate and has to be unambiguous.
Typically, such devices comprise a housing adapted to receive a cartridge at least partially filled with the medicament to be dispensed. The device further comprises a drive mechanism, typically having a displaceable piston rod which is adapted to operably engage with a piston of the cartridge. By means of the drive mechanism and its piston rod, the piston of the cartridge can be displaced in a distal or dispensing direction and may therefore expel a pre-defined amount of the medicament via a piercing assembly which is to be releasably coupled with a distal end section of the housing of the drug delivery device.
Among different types of pen injectors there exist disposable drug delivery devices which are intended to be discarded in their entirety once the medicament provided in the cartridge is used up. With these devices, empty cartridges are not to be replaced. Instead, a new drug delivery device with a filled cartridge readily arranged therein should be purchased and applied by the patient or user.
Disposable drug delivery devices may be frequently subject to misuse, in particular in combination with counterfeited medicaments. Hence, original drug delivery devices may be disassembled and an empty cartridge may be replaced by a filled one while resetting the drive mechanism intended to interact with the cartridge.
Such illegitimate manipulation of a drug delivery device implicits an undue risk of health of the patient using such a device.
It is therefore an object of the present invention to provide an anti-counterfeiting means to inhibit illegitimate manipulation of disposable drug delivery devices after their intended use. The anti-counterfeiting means should be implementable into existing drug delivery devices as smooth and easy as possible and should come along with negligible cost- and implementation efforts.